Pamukkale, meaning "cotton castle" in Turkish, is a natural site in Denizli Province in southwestern Turkey. The area is famous for its hot springs and enormous white terraces of travertine, a carbonate mineral left by the flowing water. It is located in Turkey's Inner Aegean region, in the River Menderes valley, which has a temperate climate for most of the year.The ancient Greco-Roman city of Hierapolis was built on top of the white "castle" which is in total about 2700m long, 600m wide and 160m high. It can be seen from the hills on the opposite side of the valley in the town of Denizli, 20 km away.Known as Pamukkale (Cotton Castle) or ancient Hierapolis (Holy City), this area has been drawing the weary to its thermal springs since the time of Classical antiquity. The Turkish name refers to the surface of the shimmering, snow-white limestone, shaped over millennia by calcium-rich springs. Dripping slowly down the vast mountainside, mineral-rich waters foam and collect in terraces, spilling over cascades of stalactites into milky pools below. Legend has it that the formations are solidified cotton (the area’s principal crop) that giants left out to dry.Tourism is and has been a major industry in the area for thousands of years, due to the attraction of the thermal pools. As recently as the mid-20th century, hotels were built over the ruins of Hierapolis, causing considerable damage. An approach road was built from the valley over the terraces, and motor bikes were allowed to go up and down the slopes. When the area was declared a World Heritage Site, the hotels were demolished and the road removed and replaced with artificial pools.